Citation Nr: 1320488 Decision Date: 06/25/13 Archive Date: 07/05/13 DOCKET NO. 07-11 310 ) DATE ) ) On appeal from the Department of Veterans Affairs Regional Office in Houston, Texas THE ISSUES 1. Whether new and material evidence, sufficient to reopen a claim of service connection for residuals of a low back disability has been received, and if so, whether service connection is warranted. 2. Entitlement to service connection for bilateral knee disabilities. REPRESENTATION Appellant represented by: Texas Veterans Commission WITNESS AT HEARING ON APPEAL Appellant ATTORNEY FOR THE BOARD C.L. Krasinski, Counsel INTRODUCTION The Veteran served on active duty from March 1966 to August 1987. This matter comes to the Board of Veterans' Appeals (Board) from a May 2006 rating decision by which the RO denied the Veteran's claims. In June 2010, the Veteran testified at a hearing before the undersigned Veterans Law Judge via video teleconference. The Veteran's wife also gave testimony at the hearing. A complete hearing transcript has been associated with the claims file. In September 2010, the Board remanded this case to the RO via the Appeals Management Center (AMC), in Washington, DC. In October 2012, the Board reopened the claim for service connection for bilateral knee disabilities, and remanded the claim for service connection for a bilateral knee disability and the claim to reopen service connection for a back disability for further development. In the September 2010 remand, the Board asked that the RO/AMC obtain VA medical records as well as any private treatment records identified by the Veteran. The RO obtained the available VA medical records. The Veteran did not identify any private medical treatment providers. In October 2012, the Board asked that the RO/AMC obtain VA medical records and provide the Veteran a VA examination to obtain medical evidence as to the nature and etiology of the bilateral knee disability. The RO/AMC obtained the VA treatment records, provided a VA examination on January 2013, and obtained a medical opinion in April 2013. As the requested development has been completed to the extent possible, no further action to ensure compliance with the remand directives is required. See Dyment v. West, 13 Vet. App. 141, 146-47 (1999) (remand not required under Stegall v. West, 11 Vet. App. 268 (1998), where the Board's remand instructions were substantially complied with), aff'd, Dyment v. Principi, 287 F.3d 1377 (Fed. Cir. 2002). In evaluating this case, the Board has not only reviewed the Veteran's physical claims file, but has also reviewed the Veteran's file on the "Virtual VA" system to ensure a complete assessment of the evidence. FINDINGS OF FACT 1. Service connection for a low back disability was denied by the RO in a March 1988 rating decision. The Veteran did not appeal this decision and it became final. 2. New evidence received since the March 1988 rating decision relates to unestablished facts necessary to substantiate the claim involving the claimed low back disability. 3. No disease or chronic symptoms of degenerative joint disease and disc disease of the thoracolumbar spine were manifested during service. 4. The Veteran did not continuously manifest symptoms of degenerative joint disease and disc disease of the thoracolumbar spine in the years after service. 5. Degenerative joint disease and disc disease of the thoracolumbar spine were not manifested to a degree of ten percent within one year of service separation. 6. The Veteran's degenerative joint disease and disc disease of the thoracolumbar spine are not caused by any in-service event, are not related to active service, and are not caused or aggravated by a service-connected disability including the service-connected right foot disability. 7. No disease or chronic symptoms of degenerative joint disease of the knees were manifested during service. 8. The Veteran did not continuously manifest symptoms of degenerative joint disease of the knees in the years after service. 9. Degenerative joint disease of the knees was not manifested to a degree of ten percent within one year of service separation. 10. The Veteran's degenerative joint disease of the knees is not caused by any in-service event, is not related to active service, and is not caused or aggravated by a service-connected disability including the service-connected right foot disability. CONCLUSIONS OF LAW 1. The March 1988 rating decision, which denied entitlement to service connection for a low back disability, is final. 38 U.S.C.A. § 7105(c) (West 2002); 38 C.F.R. § 20.1103 (2012). 2. The criteria for reopening the claim of entitlement to service connection for a low back disability are met. 38 U.S.C.A. § 5108 (West 2002);38 C.F.R. § 3.156(a) (2012). 3. The criteria for service connection for degenerative joint disease and disc disease of the thoracolumbar spine are not met. 38 U.S.C.A. §§ 1110, 1112, 1113, 1137, 5103, 5103A, 5107 (West 2002 & Supp. 2012); 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.307, 3.309, 3.310 (2012). 4. The criteria for service connection for degenerative joint disease of the bilateral knees are not met. 38 U.S.C.A. §§ 1110, 1112, 1113, 1137, 5103, 5103A, 5107 (West 2002 & Supp. 2012); 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.307, 3.309, 3.310 (2012). REASONS AND BASES FOR FINDINGS AND CONCLUSIONS 1. Duties to Notify and Assist The Veterans Claims Assistance Act of 2000 (VCAA) and implementing regulations imposes obligations on VA to provide claimants with notice and assistance. 38 U.S.C.A. §§ 5102, 5103, 5103A, 5107, 5126 (West 2002 & Supp. 2012); 38 C.F.R. §§ 3.102, 3.156(a), 3.159, 3.326(a) (2012). When VA receives a complete or substantially complete application for benefits, it is required to notify the claimant and the representative, if any, of any information and medical or lay evidence that is necessary to substantiate the claim. 38 U.S.C.A. § 5103(a); 38 C.F.R. § 3.159(b). VA must (1) inform the claimant about the information and evidence not of record that is necessary to substantiate the claim; (2) inform the claimant about the information and evidence that VA will seek to provide; and (3) inform the claimant about the information and evidence the claimant is expected to provide. The Board finds that the VCAA notice requirements have been satisfied by letters dated in February 2006, March 2006, May 2007, July 2007, January 2008, March 2008, September 2010, August 2012, and November 2012. In these letters, VA informed the Veteran of the evidence and information needed to substantiate a claim to reopen and a claim for service connection and informed the Veteran of which information and evidence he was to provide to VA and which information and evidence VA would attempt to obtain on his behalf. VA informed the Veteran it had to obtain any records held by any federal agency. These letters also informed the Veteran that on his behalf VA would make reasonable efforts to obtain records that were not held by a federal agency, such as records from private doctors and hospitals. Finally, the letters told the Veteran that he could obtain private records himself and submit them to VA. The VCAA notice requirements of 38 U.S.C.A. § 5103(a) and 38 C.F.R. § 3.159(b) apply to all five elements of a service connection claim. Those five elements include: (1) veteran status; (2) existence of a disability; (3) a connection between a veteran's service and the disability; (4) degree of disability; and (5) effective date of the disability. The Court held that the VCAA notice must include notice that a disability rating and an effective date of the award of benefits will be assigned if service connection was awarded. Dingess/Hartman v. Nicholson, 19 Vet. App. 473 (2006). In the present appeal, the March 2006, May 2007, and March 2008 letters explained the type of evidence necessary to establish service connection and the type of evidence necessary to establish a disability rating and effective date for the claims on appeal. The claims were readjudicated in the March 2010, March 2012, and April 2013 Supplemental Statements of the Case, thus curing any lack of timeliness of notice. Prickett v. Nicholson, 20 Vet. App. 370, 376 (2006). VA has a duty to assist a veteran in the development of the claim. This duty includes assisting the veteran in the procurement of service treatment records and pertinent treatment records and providing an examination when necessary. 38 U.S.C.A. § 5103A; 38 C.F.R. § 3.159. The Board notes that the Veteran's service treatment records are associated with the claims folder. VA treatment records dated from 1994 to October 2012 are associated with the claims folder. The RO/AMC searched for the VA treatment records dated from 1987 to 1994 and was notified by VA that the records for this time period were not available. The Veteran was notified of the results of this search in March 2012. Private medical records are associated with the claims file. In August 2007 and May 2008, the Veteran indicated that he had no additional information or evidence to submit. VA provided an examination in January 2013 to obtain medical evidence as to the nature and likely etiology of the claimed bilateral knee disability and a medical opinion was obtained in April 2013. VA provided an examination in August 2009 to obtain medical evidence as to the nature and likely etiology of the claimed low back disability and a medical opinion was obtained in April 2013. The examinations are adequate because the examinations were performed by medical professionals based on review of claims file, solicitation of history and symptomatology from the Veteran, and an examination of the Veteran. Barr v. Nicholson, 21 Vet. App. 303, 312 (2007); see also Nieves-Rodriguez v. Peake, 22 Vet. App. 295 (2008). The VA examiners considered the Veteran's service treatment records and provided a medical opinion as to whether the claimed disabilities were related to active service. Neither the Veteran nor his representative has challenged the adequacy of the examinations obtained for these issues. Sickels v. Shinseki, 643 F.3d 1362 (Fed. Cir. 2011) (holding that the Board is entitled to presume the competence of a VA examiner and the adequacy of his opinion). Accordingly, the Board finds that VA's duty to assist with respect to obtaining a VA examination or opinion has been met. 38 C.F.R. § 3.159(c)(4). For these reasons, the Board finds that the duties to notify and assist the Veteran have been met, so that no further notice or assistance to the Veteran is required to fulfill VA's duty to assist in the development of the claims. Smith v. Gober, 14 Vet. App. 227 (2000), aff'd 281 F.3d 1384 (Fed. Cir. 2002); Dela Cruz v. Principi, 15 Vet. App. 143 (2001). The Board finds that no reasonable possibility exists that any other assistance would aid in substantiating the claims and VA met its duty to assist the Veteran. In Bryant v. Shinseki, 23 Vet. App. 488 (2010), the Court held that 38 C.F.R. § 3.103(c)(2) (2012) requires that the Veterans Law Judge who conducts a hearing fulfill two duties to comply with the above the regulation. These duties consist of (1) the duty to fully explain the issues and (2) the duty to suggest the submission of evidence that may have been overlooked. Here, during the June 2010 Board hearing, the undersigned Veterans Law Judge noted the elements of service connection that were lacking to substantiate the Veteran's claims, including the need for current disabilities that are shown to be related to service. No additional pertinent evidence that might have been overlooked and that might substantiate the claims of service connection was identified by the Veteran or the representative; Therefore, the Board finds that, consistent with Bryant, the undersigned Veterans Law Judge complied with the duties set forth in 38 C.F.R. § 3.103(c)(2). 2. New and Material Evidence to Reopen the Claim for Service Connection for a Low Back Disability Law and Regulations Prior unappealed decisions of the Board and the RO are final. 38 U.S.C.A. §§ 7104, 7105(c) (West 2002 & Supp. 2012); 38 C.F.R. §§ 3.160(d), 20.302(a), 20.1100, 20.1103, 20.1104 (2012). If, however, new and material evidence is presented or secured with respect to a claim which has been disallowed, VA shall reopen the claim and review the former disposition of the claim. Manio v. Derwinski, 1 Vet. App 145 (1991). When determining whether additional evidence is new and material, VA must determine whether such evidence has been presented under 38 C.F.R. § 3.156(a) in order to have a finally denied claim reopened under 38 U.S.C.A. § 5108. New evidence means existing evidence not previously submitted to agency decision makers. 38 C.F.R. § 3.156(a). Material evidence means existing evidence that, by itself or when considered with previous evidence of record, relates to an unestablished fact necessary to substantiate the claim. New and material evidence can be neither cumulative nor redundant of the evidence of record at the time of the last prior final denial of the claim sought to be reopened, and must raise a reasonable possibility of substantiating the claim. Id. The Board has a legal duty to address the "new and material evidence" requirement regardless of the actions of the RO. If the Board finds that no new and material evidence has been submitted it is bound by a statutory mandate not to consider the merits of the case. Barnett v. Brown, 8 Vet. App. 1, 4 (1995), aff'd, 83 F.3d 1380 (Fed. Cir. 1996); see also McGinnis v. Brown, 4 Vet. App. 239, 244 (1993). In determining whether evidence is new and material, the credibility of the new evidence is to be presumed. Justus v. Principi, 3 Vet. App. 510, 513 (1992). The evidence to be considered in making this new and material determination is that added to the record since the last final denial on any basis. Evans v. Brown, 9 Vet. App. 27 (1996). See also Shade v. Shinseki, 24 Vet. App. 110, 120 (2010) (new and material evidence need not be received as to each previously unproven element of a claim in order to justify reopening thereof). Discussion Service connection was previously denied for a low back disability in a March 1988 rating decision. The Veteran was provided notice of that decision, but he did not submit a notice of disagreement with the decision and it became final. 38 U.S.C.A. § 7105(c); 38 C.F.R. § 1103; see also 38 C.F.R. § 20.200, 20.201, 20.202, 20.302 (2011) (the regulations pertaining to the procedures and time limitations for appealing adverse RO determinations to the Board). In the March 1988 rating decision, the RO denied entitlement to service connection for a low back disability because there was no evidence showing that the Veteran had a current low back disability that was a residual of the injury in service. At the time the March 1988 rating decision was issued, the evidence included the Veteran's service treatment records and a January 1988 VA examination report. The service treatment records showed that in November 1970, the Veteran sustained a minor laceration to the low back. An April 1981 x-ray examination of the thoracic spine was normal. The April 1987 separation examination report indicates that the Veteran denied having recurrent back pain. Examination of the spine was normal except for a intraumbilical nevoid lesions compound nevus on the right lumbosacral area. The January 1988 VA examination report indicates that the Veteran reported having constant back pain. X-ray examination of the lumbar spine was normal. The diagnosis was back injury with residuals of chronic low back strain. The Board has reviewed the evidence submitted to the record since the January 1988 rating decision and finds that new and material evidence has been received. An August 2009 VA examination report indicates that the Veteran reported that he had mild low back pain since a motor vehicle accident in service. The diagnosis was mild diffuse degenerative disc disease at all levels of the thoracolumbar spine. The examiner opined that the lumbar spine degenerative disc disease was less likely than not due to the motor vehicle accident in service but were age related degenerative changes. A May 2010 lumbar spine MRI showed degenerative changes at multiple levels. The April 2013 VA medical opinion indicates that the lumbar spine disability was not due to the service-connected right foot disability. The May 2009 VA examination report, the May 2010 MRI report, and the April 2013 VA medical opinion were not of record prior to the issuance of the March 1988 rating decision and are not duplicative or cumulative of the evidence that was of record at the time of the March 1988 rating decision. This evidence is new. The Board also finds that this evidence is material within the meaning of applicable law and regulations because it is probative of the issue at hand, which is whether the Veteran has a current low back disability that is related to his period of active duty service. This medical evidence establishes diagnosis of degenerative disc disease and degenerative joint disease of the thoracolumbar spine. At the May 2009 VA examination, the Veteran provided lay statements as to a low back injury in service in the motor vehicle accident. This newly submitted evidence is material because it is pertinent to the circumstances surrounding the origin and date of onset of the claimed low back disability. This evidence provides a "more complete picture of the circumstances surrounding the origin of the Veteran's injury or disability, even where it will not eventually convince the Board to alter its decision." See Hodge v. West, 155 F.3d 1356 (Fed. Cir. 1998). Thus, the Board finds that this evidence is new and material. Thus, the Board finds that the newly added evidence relates to unestablished facts necessary to substantiate the Veteran's claim of service connection for a low back disability. 38 C.F.R. § 3.156(a). Accordingly, the Veteran's claim of service connection for a low back disability is reopened. To that extent only, the claim is granted. 3. Entitlement to Service Connection Laws and Regulations Service connection will be granted for disability resulting from a disease or injury incurred in or aggravated by military service. 38 U.S.C.A. §§ 1110, 1131; 38 C.F.R. § 3.303. Service connection may also be granted for a disease first diagnosed after discharge when all of the evidence, including that pertinent to service, establishes that the disease was incurred in service. 38 C.F.R. § 3.303(d). Service connection requires competent evidence showing, (1) the existence of a present disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a causal relationship between the present disability and the disease or injury incurred or aggravated during service. Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004), citing Hansen v. Principi, 16 Vet. App. 110, 111 (2002); see also Caluza v. Brown, 7 Vet. App. 498 (1995). In this case, arthritis is listed among the "chronic diseases" under 38 C.F.R. § 3.309(a); therefore, 38 C.F.R. § 3.303(b) applies. Walker v. Shinseki, 708 F.3d 1331 (Fed. Cir. 2013). Where the evidence shows a "chronic disease" in service or "continuity of symptoms" after service, the disease shall be presumed to have been incurred in service. For the showing of "chronic" disease in service, there is required a combination of manifestations sufficient to identify the disease entity, and sufficient observation to establish chronicity at the time. With chronic disease as such in service, subsequent manifestations of the same chronic disease at any later date, however remote, are service-connected, unless clearly attributable to intercurrent causes. If a condition noted during service is not shown to be chronic, then generally, a showing of "continuity of symptoms" after service is required for service connection. 38 C.F.R. § 3.303(b). Additionally, where a veteran served ninety days or more of active service, and certain chronic diseases, such as arthritis, become manifest to a degree of 10 percent or more within one year after the date of separation from such service, such disease shall be presumed to have been incurred in service, even though there is no evidence of such disease during the period of service. 38 U.S.C.A. §§ 1101, 1112, 1113; 38 C.F.R. §§ 3.307, 3.309(a). While the disease need not be diagnosed within the presumption period, it must be shown, by acceptable lay or medical evidence, that there were characteristic manifestations of the disease to the required degree during that time. Id. Service connection can be granted for a disability that is aggravated by a service-connected disability. Compensation can be paid for any additional impairment resulting from the service-connected disability. 38 C.F.R. § 3.310; Allen v. Brown, 7 Vet. App. 439 (1995). Except as provided in 38 C.F.R. § 3.300(c) (claims for secondary service connection based on the effects of tobacco products received after June 9, 1998), disability which is proximately due to or the result of a service-connected disease or injury shall be service connected. When service connection is thus established for a secondary condition, the secondary condition shall be considered a part of the original condition. 38 C.F.R. § 3.310(a). Any increase in severity of a nonservice-connected disease or injury that is proximately due to or the result of a service-connected disease or injury, and not due to the natural progress of the nonservice-connected disease, will be service connected. 38 C.F.R. § 3.310(b). VA will not concede that a nonservice-connected disease or injury was aggravated by a service-connected disease or injury unless the baseline level of severity of the nonservice-connected disease or injury is established by medical evidence created before the onset of aggravation or by the earliest medical evidence created at any time between the onset of aggravation and the receipt of medical evidence establishing the current level of severity of the nonservice- connected disease or injury. The rating activity will determine the baseline and current levels of severity under the Schedule for Rating Disabilities (38 CFR part 4) and determine the extent of aggravation by deducting the baseline level of severity, as well as any increase in severity due to the natural progress of the disease, from the current level." Id. With disability compensation claims, VA adjudicators are directed to assess both medical and lay evidence. As a general matter, a layperson is not capable of opining on matters requiring medical knowledge. See 38 C.F.R. § 3.159(a)(2). In certain circumstances, however, lay evidence may be sufficient to establish a medical diagnosis or nexus. See Davidson v. Shinseki, 581 F.3d 1313, 1316 (Fed. Cir. 2009). In addressing lay evidence and determining its probative value, if any, attention is directed to both competency ("a legal concept determining whether testimony may be heard and considered") and credibility ("a factual determination going to the probative value of the evidence to be made after the evidence has been admitted"). See Layno v. Brown, 6 Vet. App. 465, 469 (1994). In terms of competency, lay evidence has been found to be competent with regard to a disease with "unique and readily identifiable features" that is "capable of lay observation." See Barr v. Nicholson, 21 Vet. App. 303, 308-09 (2007) (concerning varicose veins); see also Jandreau v. Nicholson, 492 F.3d 1372, 1376-77 (Fed. Cir. 2007) (a dislocated shoulder); Charles v. Principi, 16 Vet. App. 370, 374 (2002) (tinnitus); Falzone v. Brown, 8 Vet. App. 398, 405 (1995) (flatfoot). That notwithstanding, a veteran is not competent to provide evidence as to more complex medical questions and, specifically, is not competent to provide an opinion as to etiology in such cases. See Woehlaert v. Nicholson, 21 Vet. App. 456, 462 (2007) (concerning rheumatic fever). In weighing credibility, VA may consider interest, bias, inconsistent statements, bad character, internal inconsistency, facial plausibility, self-interest, consistency with other evidence of record, malingering, desire for monetary gain, and demeanor of the witness. See generally Caluza v. Brown, 7 Vet. App. 498 (1995). The Board may weigh the absence of contemporaneous medical evidence against the lay evidence in determining credibility, but the Board cannot determine that lay evidence lacks credibility merely because it is unaccompanied by contemporaneous medical evidence. See Buchanan v. Nicholson, 451 F.3d 1331, 1335 (Fed. Cir. 2006); but see Maxson v. Gober, 230 F.3d 1330 (Fed. Cir. 2000) (evidence of a prolonged period without medical complaint after service can be considered along with other factors in the analysis of a service connection claim). When there is an approximate balance of positive and negative evidence regarding any issue material to the determination of a matter, the Secretary shall give the benefit of the doubt to the claimant. 38 U.S.C.A. § 7105; 38 C.F.R. §§ 3.102, 4.3, 4.7. Analysis Service Connection for a Low Back Disability The Veteran contends that his current low back disability was incurred in service. In the November 1987 initial claim for service connection, the Veteran asserted that he had a back injury due to a motor vehicle accident in service. In an August 2006 statement, the Veteran indicated that he had several attacks of severe pain in the low back in service. He stated that to the best of his knowledge, this first happened in between 1980 to 1985, in the fall. The Veteran indicated that he was placed on bed rest and on pain pills and he was not able to get out of bed without assistance. In a February 2007 statement, the Veteran stated that he received treatment for his low back in service between 1980 to 1987; he had horrible spasms in his back and he could not move. He stated that his current back disability could also stem from the automobile accident in service and the fact that he has severe flat feet and hammer toes. In an April 2007 statement, the Veteran argued that the trauma to his neck caused the trauma to the lumbar spine when he flipped a one and a half ton truck in service; he asserted that he had a compression fracture to the lower spine in addition to the neck fracture. He asserted that the herniated disc could only have occurred in service. At the May 2009 VA examination report indicates that the Veteran reported that he began to have low back pain and stiffness since the motor vehicle accident in service. At the June 2010 Board video conference hearing, the Veteran stated that he was in a motor vehicle accident in service in 1980. He reported that his vehicle was hit by another vehicle, it flipped over, and he was crushed in the seat. He stated that this was the start of his back pain, he had back spasms in service, and the spasm episodes would last about six months and sometimes a year. The Veteran indicated that after service, he underwent four epidural injections. See the June 2010 Board video conference hearing transcript. There is competent evidence of a current low back disability. An August 2009 VA examination report shows a diagnosis of mild diffuse degenerative disc disease at all levels of the thoracolumbar spine. A May 2010 lumbar spine MRI showed degenerative changes at multiple levels. The Board finds the weight of the competent and credible evidence shows that the degenerative disc disease and degenerative changes of the thoracolumbar spine did not manifest in service or within one year of service separation and are not related to active service. The Board finds that the degenerative changes of the thoracolumbar spine is a "chronic disease" listed under 38 C.F.R. § 3.309(a), and the provisions of 38 C.F.R. § 3.303(b) are applicable. See Walker, supra. However, the Board finds that the weight of the competent and credible evidence establishes that the Veteran did not experience "chronic" symptoms of back pain during service, he did not have continuous or chronic low back symptoms since service, and the degenerative disc disease and degenerative changes of the thoracolumbar spine first manifested many years after service separation and are not related to disease or injury in service but are related to the normal aging process. Thus, presumptive service connection for degenerative disc disease and degenerative changes of the thoracolumbar spine under the provisions of 38 C.F.R. § 3.303(b) is not warranted. The Board finds that the weight of the competent and credible evidence establishes that the Veteran did not have chronic symptoms of back pain in service or continuously after service. The service treatment records and the Veteran's own lay statements made during his period of active service do not establish that the Veteran had chronic symptoms of back pain in service. The service treatment records show that upon enlistment examination in September 1965, examination of the spine was normal. A November 1970 service treatment record indicates that the Veteran sustained a minor laceration to the low back. A February 1980 service treatment record indicates that the Veteran was in a motor vehicle accident and he twisted his neck. The record indicates that he denied chest, back, or extremity pain. The assessment was scalp laceration and cervical spine strain. An April 1981 x-ray examination of the thoracic spine was normal. An April 1982 examination report indicates that examination of the spine was normal. The April 1987 separation examination report indicates that the Veteran denied having recurrent back pain. Examination of the spine was normal except for a intraumbilical nevoid lesion compound nevus on the right lumbosacral area. The Veteran first asserted that he had a back injury due to a motor vehicle accident in service in a November 1987 application for compensation benefits. He first reported having constant back pain at the January 1988 VA examination. The Veteran did not report sustaining injuries in a motor vehicle accident in service. X-ray examination of the lumbar spine was normal. Examination revealed no pain on palpation and no tenderness. Forward flexion of the thoracolumbar spine was to 95 degrees. The diagnosis was back injury with residuals of chronic low back strain. A July 2000 VA treatment record notes that the Veteran had minor degenerative joint disease of the thoracic spine. Review of the record shows that the next documented complaint of low back pain was in 2002. A June 2002 VA treatment record indicates that the Veteran complained of acute low back pain for two days after bending. Physical examination revealed forward flexion to 75 degrees and moderate to severe muscle spasm. The assessment was acute low back pain possibly secondary to L5-S1 disc disease. A June 2002 x-ray examination of the lumbar spine revealed mild osteophyte formation of the lumbar end plates and T11 and t12, moderate narrowing at L5-S1 disc space, mild degenerative sclerosis at L4-L5 facet joints, and slight anterior wedging at T11 to L2. An April 2003 VA treatment record notes that the Veteran continued to have low back pain. It was noted that he had severe low back pain in November and had an epidural injection. The assessment was degenerative joint disease and lumbar disc disease. See also VA treatment records and/or x-ray examination reports dated in January 2006, July 2009, May 2010, and February 2011 which show diagnoses of degenerative joint disease and degenerative disc disease of the lumbar spine. An August 2009 VA examination report indicates that the Veteran reported that he had mild low back pain since a motor vehicle accident in service. The diagnosis was mild diffuse degenerative disc disease at all levels of the thoracolumbar spine. The examiner opined that the lumbar spine degenerative disc disease was less likely than not due to the motor vehicle accident in service but were age related degenerative changes. The examiner noted that he had reviewed the service treatment records and there was no evidence of a lumbar spine injury at the time of the motor vehicle accident. The examiner opined that the degenerative disc disease were normal age related degenerative changes and that traumatic injury typically show focal degenerative changes. The Veteran is competent to report observable symptoms such as back pain. See Jandreau; supra. However, the Board finds that the Veteran's statements that he had chronic low back pain in service and since active service are not credible and. The Veteran's statements concerning the onset of the back pain are inconsistent and are not supported by the service treatment records or his own statements made during his period of service. Service records show that the Veteran denied having back pain when he was being treated for injuries due to the motor vehicle accident in 1980. He denied having recurrent back pain upon service separation examination in April 1987. The service treatment record do not documents severe episodes of back pain in the 1980's or any injury to the low back following the 1980 motor vehicle accident. The Veteran reported having constant back pain upon VA examination in January 1988. The Veteran did not report that this back pain was continuous since service. Degenerative joint disease or disc disease were not diagnosed at that time. The diagnosis was back injury with residuals of chronic back strain. The Veteran's statements that he had back pain in service and since service are not supported by his own statements made to health care providers after service. Prior to filing his claim for compensation, the Veteran attributed the low back pain to acute injuries. See the June 2002 VA treatment record. The Veteran filed his application to reopen the claim for service connection for a low back disability in January 2006. In 2009, the Veteran began to report a long history of back pain since service. The Veteran reported that he had back pain since the motor vehicle accident in service upon VA examination in August 2009. In weighing credibility, VA may consider interest, bias, inconsistent statements, bad character, internal inconsistency, facial plausibility, self interest, consistency with other evidence of record, malingering, desire for monetary gain, and demeanor of the witness. Caluza v. Brown, 7 Vet. App. 498 (1995). Thus, the Board finds that the Veteran's statements that he has had chronic and continuous low back pain since active service are not credible and are not probative because these statements were made many years after service and were made in connection with the Veteran's claim for compensation. The Board finds that the statements that the Veteran made during service and at service separation and the findings shown in the service treatment records to have more probative value than the statements made by the Veteran many years after service separation. The Veteran's in-service statements were made contemporaneous to the time of the claimed injury and were made in the course of medical treatment and examination. This probative evidence establishes that the Veteran did not have chronic and continuous back pain symptoms in service and since service separation. At the video conference hearing before the Board in June 2010, the Veteran's spouse also testified that the Veteran's has had back problems since service. The Board finds that these statements have limited probative value as well. The spouse's statements are competent evidence but have limited credibility since the statements were made many years after service and were made in connection with the Veteran's claim for compensation. These statements are outweighed by the Veteran's statements made in service and the findings shown in the service treatment records. There is no competent evidence of a diagnosis of degenerative joint disease or degenerative disc disease of the lumbar spine within one year of service separation. The January 1988 VA X-ray examination of the lumbar spine yielded normal results. The first x-ray evidence of degenerative joint disease of the thoracolumbar spine was in 2000, over 10 years after service separation. Lumbar spine disc disease was first diagnosed in 2003. Finally, the Board finds that the weight of the evidence demonstrates that degenerative joint disease and degenerative disc disease of the lumbar spine are not caused by any in-service event or injury and are not medically related to service. The Veteran was afforded a VA examination in August 2009. The VA examiner reviewed the claims folder, considered the Veteran's reported medical history, examined the Veteran, and offered an opinion as to the etiology of the claimed lumbar spine disability. The VA examiner opined that the Veteran's current degenerative joint disease and degenerative disc disease first manifested many years after service and are not related to injury or disease in active service but are normal age related degenerative changes. As noted above, the examiner also noted that he reviewed the service treatment records and found that there was no evidence of a lumbar spine injury at the time of the motor vehicle accident and the current lumbar spine disability was less likely as not due to motor vehicle accident in service. The Board finds the August 2009 VA medical opinion to have great evidentiary weight as the opinion reflects a comprehensive and reasoned review of the entire evidentiary record. The VA examiner reviewed the claims folder including the service treatment records and the Veteran's medical history, and examined the Veteran before rendering the medical opinion. The VA examiner specifically addressed the service treatment records for the injuries due to the motor vehicle accident in service and discussed the examination findings and considered such findings when rendering the medical opinion. Factors for assessing the probative value of a medical opinion are the examiner's access to the claims file and the thoroughness and detail of the opinion. See Hernandez-Toyens v. West, 11 Vet. App. 379, 382 (1998); see also Prejean v. West, 13 Vet. App. 444, 448-9 (2000). The medical opinion is based on sufficient facts and data. In Nieves-Rodriguez, 22 Vet. App. 295, the Court held that guiding factors in evaluating the probity of a medical opinion are whether the opinion was based on sufficient facts or data, whether the opinion was the product of reliable principles and methods, and whether the medical professional applied the principles and methods reliably to the facts of the case. For these reasons, the Board has assigned great probative weight to the opinion of the VA physician and finds that it outweighs the unsupported lay theories and lay statements of the Veteran and establishes that the Veteran's degenerative joint disease and degenerative disc disease of the lumbar spine are not related to active service and are due to the aging process. The Board notes that in the April 2013, the examiner indicated that in her opinion, the etiology of the low back condition was the Veteran's military occupation specialty in service and the excessive squatting and kneeling. The Board finds that this statement alone is not sufficient to establish a nexus between the current degenerative joint disease and degenerative disc disease of the lumbar spine to service. The examiner does not provide the reasons and bases for this medical conclusion and does not point out the factual or medical basis for this conclusion. The examiner also concluded that the lumbar spine disability was consistent with the normal aging process. The Court has held that medical opinions that are general or inconclusive in nature cannot support a claim. See Obert v. Brown, 5 Vet. App. 30, 33 (1993); Bloom v. West, 12 Vet. App. 185, 187 (1999). Factors for assessing the probative value of a medical opinion are the examiner's access to the claims file and the thoroughness and detail of the opinion. See Hernandez-Toyens; supra. A medical opinion must be based on sufficient facts and data. See Nieves-Rodriguez; supra. The Board finds that the April 2013 VA medical opinion as to the etiology of the lumbar spine disability is outweighed by the May 2009 VA medical opinion and is not sufficient evidence to establish a medical relationship between the current lumbar spine disability and active service. The Veteran himself has related his degenerative joint disease and degenerative disc disease of the lumbar spine to his active service. As noted, the Veteran, as a lay person, is competent to describe observable symptoms such as pain. Although lay persons are competent to provide opinions on some medical issues, see Kahana v. Shinseki, 24 Vet. App. 428, 435 (2011), as to the specific issue in this case, an opinion as to the etiology and onset of arthritis or disc disease falls outside the realm of common knowledge of a lay person. See Jandreau, 492 F.3d at 1377 n.4 (lay persons not competent to diagnose cancer). Some medical issues require specialized training for a determination as to diagnosis and causation, and such issues are therefore not susceptible of lay opinions on etiology. Lay testimony on the question of relating the current degenerative joint disease and degenerative disc disease to service is not competent in the present case, because the Veteran is not competent to state that this disease was incurred in service. See Davidson v. Shinseki, 581 F.3d 1313, 316 (Fed. Cir. 2009); Kahana v. Shinseki, 24 Vet. App. 428, 433, n. 4 (2011) (lay witnesses are competent to opine as to some matters of diagnosis and etiology, and the Board must determine on a case by case basis whether a veteran's particular disability is the type of disability for which lay evidence is competent). Such diagnoses requires clinical or diagnostic testing such as x-ray examination. X-ray examination in service and soon after service were negative. Additionally, an opinion of etiology would require knowledge of the complexities of the musculoskeletal system and the various causes of arthritis, and would involve objective clinical testing that the Veteran is not competent to perform. For the reasons and bases discussed above, the Board finds that a preponderance of the lay and medical evidence that is of record weighs against the claim for service connection for degenerative joint disease and degenerative disc disease of the lumbar spine including as a presumptive disease and on a direct basis, and the claim must be denied. The Veteran also argues that his service-connected right foot disability and the service-connected cervical spine disability caused or aggravated the claimed degenerative joint disease and degenerative disc disease of the lumbar spine. Service connection for pes planus; hammertoes at 2, 3, and 4; heel spurs; degenerative joint disease of the talonavicular joint, bilateral, and degenerative changes of the subtalar joint of the right foot were granted in March 1988 and a 30 percent rating was assigned from September 1, 1987. Service connection is also in effect for residuals of cervical strain with traumatic narrowing at C4-5 and a 10 percent rating has been in effect since April 22, 2003. There is no competent medical evidence of record indicating that the current degenerative joint disease and degenerative disc disease of the lumbar spine were caused or aggravated by the service-connected right foot disability or any other service-connected disability. The record contains many medical treatment notations regarding the lumbar spine but at no time did a physician or other medical professional express an opinion regarding a link between the current lumbar spine disability and the service-connected right foot disability or other service-connected disability. There is competent and credible evidence which establishes that there is no relationship between the degenerative joint disease and degenerative disc disease of the lumbar spine and the service-connected right foot disability. In April 2013, VA sought a medical opinion as to whether the current lumbar spine disability was proximately due to the service-connected right foot disability to include pes planus. The examiner opined that it was less likely than not that the lumbar spine disability was proximately due to or aggravated by the service-connected right foot disability. The VA examiner opined that the lumbar spine disability was consistent with the normal aging process and it was less likely that the lumbar spine disability was aggravated beyond the normal aging process. The examiner stated that there was no medically based clinical evidence to support an etiology of flat feet for the claimed back condition. The examiner indicated that the conclusion was based upon a comprehensive review of the clinical file, CAPRI, radiographs, and current literature. Because the Veteran does not possess the necessary medical expertise to render an opinion as to the cause of a disease, his assertions do not constitute competent evidence upon which the Board may rely. An opinion as to the etiology and onset of arthritis falls outside the realm of common knowledge of a lay person. See Jandreau, 492 F.3d at 1377 n.4 (lay persons not competent to diagnose cancer). Some medical issues require specialized training for a determination as to diagnosis and causation, and such issues are therefore not susceptible of lay opinions on etiology. There is no competent evidence which relates the current degenerative joint disease and degenerative disc disease of the lumbar spine to the service-connected cervical spine disability. The weight of the competent and probative evidence establishes that there is no medical relationship to and no aggravation by a service-connected disability. As such, service connection for degenerative joint disease and degenerative disc disease of the lumbar spine as secondary to the service-connected right foot disability or other service-connected disability is denied. 38 C.F.R. § 3.310; Allen, supra. For the reasons and bases discussed above, the Board finds that a preponderance of the lay and medical evidence that is of record weighs against the claim for service connection for degenerative joint disease and degenerative disc disease of the lumbar spine including as a presumptive disease, on a direct basis, and on a secondary basis, and the claim must be denied. Service Connection for a Bilateral Knee Disability The Veteran contends that his current knee disabilities are related to the symptoms and knee injuries in service. Regarding the left knee, in a September 1965 report of medical history, the Veteran denied knee problems. The lower extremities were found to be normal on the induction physical. In April 1966 the Veteran voiced complaints of left knee pain since falling down stairs a year and a half earlier. There was reduced range of motion. A December 1973 service treatment record revealed a left knee injury that occurred two years earlier. An X-ray study of the left knee was normal. However, that month, a physical profile was issued for a strained left knee due to a possible mild ligamentous injury. A December 1973 medical examination report revealed that range of motion and strength of the lower extremities was within normal limits and that knee trouble began two years earlier but that no abnormalities were found on September 1972 X-ray study. A December 1977 medical examination report reflected normal lower extremities. In a December 1979 report of medical history, the Veteran denied knee trouble. An April 1982 medical examination indicated normal lower extremities. On separation examination in April 1987, the Veteran's lower extremities were found to be normal. In the report of medical history on separation, the Veteran denied knee trouble. Regarding the right knee, in a September 1965 report of medical history, the Veteran denied knee problems. The lower extremities were found to be normal on the induction physical. In May 1972, the examiner noted a history of right knee stress since June 1972. The diagnosis was of pain secondary to a soft tissue injury. In August 1972, the Veteran sought treatment for chronic right knee discomfort made worse by kneeling or squatting. The examiner noted an old right patella injury. A one-month profile was advised. A December 1973 medical examination report revealed that range of motion and strength of the lower extremities was within normal limits and that knee trouble began two years earlier but that no abnormalities were found on September 1972 X-ray study. A December 1977 medical examination report reflected normal lower extremities. In a December 1979 report of medical history, the Veteran denied knee trouble. An April 1982 medical examination indicated normal lower extremities. On separation examination in April 1987, the Veteran's lower extremities were found to be normal. In the report of medical history on separation, the Veteran denied knee trouble. The Veteran separated from service in August 1987. The Board finds the weight of the competent and credible evidence shows that the degenerative joint disease of the left and right knees did not manifest in service or within one year of service separation and is not related to active service. The Board finds that the degenerative joint disease of the left and right knees is a "chronic disease" listed under 38 C.F.R. § 3.309(a), and the provisions of 38 C.F.R. § 3.303(b) are applicable. See Walker, supra. However, the Board finds that the weight of the competent and credible evidence establishes that the Veteran did not experience "chronic" symptoms of left and right knee pain during service, he did not have continuous or chronic left and right knee symptoms since service, and the degenerative joint disease of the left and right knees first manifested many years after service separation and is not related to disease or injury in service. Thus, presumptive service connection for left and right knee degenerative joint disease under the provisions of 38 C.F.R. § 3.303(b) is not warranted. The Board finds that the weight of the competent and credible evidence establishes that the Veteran had symptoms of left knee pain from 1966 to 1973 and symptoms of right knee pain and a soft tissue injury of the right knee in 1972. However, subsequent to those episodes of knee pain, examination of the left and right knees was normal and the service treatment records do not document chronic or recurrent knee symptoms. Examination of the lower extremities in December 1973, December 1977, April 1982, and April 1987 were normal. X-ray examination of the knees was normal. The January 1988 VA examination report indicates that the Veteran reported having "occasional" knee pain. The record shows that at times, the Veteran sought treatment for knee pain. A November 1997 x-ray examination report indicates that the Veteran reported having pain in the knees since the 1970's when he was in service and worked on the flight line. He reported that he had to do a lot of kneeling. The Veteran indicated that he now had pain that would come and go. It was noted that the pain was inconsistent. X-ray examination revealed degenerative joint disease of the knees. In August 2000, the Veteran complained of left knee swelling that began five days earlier and indicated that similar symptoms had been occurring for several years. The Veteran reported that over the past several years, the left knee would occasionally catch. At that time, the Veteran was undergoing physical therapy for his knee. The assessment was left knee pain, possibly an acute strain. An April 2002 VA progress note shows a diagnosis of bilateral degenerative joint disease of the knees. In August 2010, the Veteran reported having pain in the right knee. The Veteran indicated that he was told decades ago in the military that he had degenerative joint disease in the knee from kneeling on the flight line. It was noted that he had twisted his knee one or two months prior and was feeling worse since then. The assessment was degenerative joint disease of the right knee. The Veteran reported having continuous knee symptoms in service and since service was when he was examined for VA in May 2007. On May 2007 VA fee-basis medical examination, the Veteran reported bilateral knee problems for 35 years due to injuries sustained while kneeling on concrete in service when repairing airplanes. He reported having symptoms of weakness and giving way. The examiner noted bilateral knee tenderness and limitation of motion with normal knees on X-ray bilaterally. The diagnosis was bilateral knee strain and the examiner stated that the residuals of the Veteran's bilateral knee injuries were bilateral tenderness, crepitus, and reduced range of motion with right knee pain and left knee grinding and popping. In subsequent statements submitted by the Veteran in support of his claim for compensation, he reported having knee symptoms since the injury in service. At the June 2010 videoconference hearing, the Veteran testified that his bilateral knee problems originated from work on the flight line. The Veteran is competent to report an observable symptoms such as knee pain. See Jandreau; supra. However, the Board finds that the Veteran's statements that he has had knee pain since active service are not credible because the Veteran first made these statements over 10 years after service separation and these statements were made in connection with his claims for compensation benefits. As noted, the Veteran first asserted that he had continuous knee pain for 35 years at the May 2007 examination. Prior to this examination, the Veteran had reported having occasional knee pain or he just reported having pain. See the September 1997 VA treatment record. Further, these statements are inconsistent with the Veteran's own statements made at service separation and upon VA examination in January 1988. Upon service separation examination in April 1987, he denied having knee symptoms. At the January 1988 VA examination, he reported having occasional knee pain. The Board finds that the lay assertions that he has had knee pain since active service which were made by the Veteran at the time he filed the applications to reopen the claims for service connection for a right and left knee disability in 2006 and 2007 and since that time are of limited probative worth when compared to the lay statements made by the Veteran during service and the statements the Veteran made to his health care providers prior to 2007. In weighing credibility, VA may consider interest, bias, inconsistent statements, bad character, internal inconsistency, facial plausibility, self interest, consistency with other evidence of record, malingering, desire for monetary gain, and demeanor of the witness. Caluza v. Brown, 7 Vet. App. 498 (1995). Thus, the Board finds that the Veteran's statements that he has had chronic and continuous knee pain since active service are not credible or probative. The Board finds that the statements that the Veteran made at service separation in which he denied having knee trouble, and the Veteran's statements made in the course of treatment after service separation and the medical evidence of record, including the January 2013 VA medical opinion, have more probative value and establish that the Veteran did not have chronic and continuous symptoms since service separation and his current arthritis of the knees first manifested many years after service and is not related to injury or disease in active service. At the video conference hearing before the Board in June 2010, the Veteran's spouse testified that the Veteran's has had knee problems since service. The Board finds that these statements have limited probative value as well. The spouse's statements are competent evidence but have limited credibility since the statements were made many years after service and were made in connection with the Veteran's claim for compensation. These statements are outweighed by the Veteran's statements made in service and the findings shown in the service treatment records. There is no competent evidence of a diagnosis of degenerative joint disease of the left and right knees within one year of service separation. The Veteran was afforded a VA examination in January 1988. X-ray study of the left knee yielded normal results. Examination of the knees was negative and there was full range of motion. The examiner diagnosed a bilateral knee condition manifested by pain. The first x-ray evidence of degenerative joint disease of the knees was in 1997. An October 1997 x-ray examination of the bilateral knees revealed mild degenerative joint disease. Finally, the Board finds that the weight of the evidence demonstrates that degenerative joint disease of the knees are not caused by any in-service event or injury and are not medically related to service. The Veteran was afforded a VA examination in January 2013. The VA examiner reviewed the claims folder, considered the Veteran's reported medical history, examined the Veteran, and offered an opinion as to the etiology of the claimed knee disabilities. The examiner indicated that the Veteran reported that he was in service from 1966 to 1987 and he had no problems with his knees prior to service. The Veteran reported that he worked beneath airplanes and kneeled on concrete. He stated that he had locking of both knees and he was seen but he does not know if there were x-rays or if there was a diagnosis. The Veteran reported that his only treatment was using a stool so he could sit when working. He reported that he was seen about 5 times by physicians. The Veteran reported that after service, he worked in various jobs, mainly custodial. The Veteran reported that he was not sure when he was first seen for evaluation after discharge. He reported that his knee problem became gradually worse and he was recently treated with injections. The Veteran underwent physical examination and the diagnosis was osteoarthritis of both knees. The examiner opined that it was less likely than not that the osteoarthritis of the left and right knees was related to service. The examiner indicated that review of service treatment records show that the Veteran sought medical treatment for left knee pain after a fall in 1966. A December 1973 service treatment record indicates that the veteran complained of left knee pain with report of a left knee injury in 1971; x-ray examination was normal. This was treated with a physical profile. Further medical examination in December 1973 showed no significant abnormalities. Regarding the right knee, the examiner indicated that service treatment records showed that the veteran had complaints of right knee pain in May and June 1972. In August 1972, the Veteran had a complaint of chronic right knee made worse by moving or squatting or suggestive patellofemoral syndrome; patella injury was noted, not acute. In December 1973, the Veteran complained of 2 years of knee pain but there were no examination abnormalities. Examinations of the lower extremities in December 1973, December 1977, April 1982, and April 1987 were normal. Regarding the left knee pain complaints, the examiner stated that there were complaints of left knee pain in 1966 and 1973, a history of 2 episodes of knee pain separated by 7 years without follow-up examination. The examiner noted that the Veteran then served for 14 years after that time without apparent difficulty. Regarding the right knee complaints, the examiner stated that the Veteran had right knee complaints in May, June, and August of 1972. The examiner stated that the visit in August 1972 was suggestive of patellofemoral syndrome and further treatment was noted in 1973. The examiner noted that this showed treatment of right knee pain between May 1972 and December 1973, a period of approximately 18 months and 4 visits were noted at that time. The examiner noted that the Veteran served an additional 14 years without complaints noted on several medical examinations and he had no new complaints of separation examination. Regarding x-ray examination of the knees, the examiner pointed out that the Veteran had negative x-ray examinations in service with the only exception was the August 1972 x-ray examination which suggested an old patella injury of the right knee with no further explanation. The examiner stated that the x-ray examination in 1997 showed minor degenerative changes and x-ray examination in 2000 showed minor degenerative changes for the left knee and bilateral tricompartmental arthritis compatible with normal aging in 2013 at age 61. The examiner indicated that in summary, the Veteran had visits for treatment of the knees in service without a specific diagnosis present for 18 months at the longest with no complaints for 14 years prior to discharge and the separation examination was negative for complaints of knee pain. The examiner further stated that the records were silent for a period of approximately 24 years (14 years in service and 10 years after service) for documented complaints or treatment. The examiner stated that there was no history of documented continuing complaints or treatment to indicate a chronic disabling condition related to military service. The examiner indicated that at the time of the Veteran's complaints after service in 1997, he was 51 years old. The examiner indicated that physical examination and x-ray changes were compatible with his age and senescence. The Board finds the January 2013 VA medical opinion to have great evidentiary weight as the opinion reflects a comprehensive and reasoned review of the entire evidentiary record. The VA examiner reviewed the claims folder including the service treatment records and the Veteran's medical history, and examined the Veteran before rendering the medical opinion. The VA examiner specifically addressed the treatment of the left knee and right knee in service and discussed the examination findings and considered such findings when rendering the medical opinion. Factors for assessing the probative value of a medical opinion are the examiner's access to the claims file and the thoroughness and detail of the opinion. See Hernandez-Toyens v. West, 11 Vet. App. 379, 382 (1998); see also Prejean v. West, 13 Vet. App. 444, 448-9 (2000). The medical opinion is based on sufficient facts and data. In Nieves-Rodriguez, 22 Vet. App. 295, the Court held that guiding factors in evaluating the probity of a medical opinion are whether the opinion was based on sufficient facts or data, whether the opinion was the product of reliable principles and methods, and whether the medical professional applied the principles and methods reliably to the facts of the case. For these reasons, the Board has assigned great probative weight to the opinion of the VA physician and finds that it outweighs the unsupported lay theories and lay statements of the Veteran and establishes that the Veteran's arthritis of the knees is not related to active service and is due to the aging process. The Board notes that in the April 2013 VA opinion, the examiner indicated that in her opinion, the etiology of the knee condition was the Veteran's military occupation specialty in service and the excessive squatting and kneeling. The Board finds that this statement alone is not sufficient to establish a nexus between the current knee disability and service. The examiner does not provide the reasons and bases for this medical conclusion and does not point out the factual or medical basis for this conclusion. The examiner also concluded that the knee disability was consistent with the normal aging process and she indicated that she was in full agreement with the January 2013 VA medical opinion (which found that the knee disability was due to aging and was not related to service). The Court has held that medical opinions that are general or inconclusive in nature cannot support a claim. See Obert v. Brown, 5 Vet. App. 30, 33 (1993); Bloom v. West, 12 Vet. App. 185, 187 (1999). Factors for assessing the probative value of a medical opinion are the examiner's access to the claims file and the thoroughness and detail of the opinion. See Hernandez-Toyens; supra. A medical opinion must be based on sufficient facts and data. See Nieves-Rodriguez; supra. The Board finds that the April 2013 VA medical opinion as to the etiology of the knee disability is outweighed by the January 2013 VA medical opinion and is not sufficient evidence to establish a medical relationship between the current knee disability and active service. The Veteran himself has related his degenerative arthritis of the left and right knees to his active service. As noted, the Veteran, as a lay person, is competent to describe observable symptoms such as pain or difficulty breathing. Although lay persons are competent to provide opinions on some medical issues, see Kahana v. Shinseki, 24 Vet. App. 428, 435 (2011), as to the specific issue in this case, an opinion as to the etiology and onset of arthritis falls outside the realm of common knowledge of a lay person. See Jandreau, 492 F.3d at 1377 n.4 (lay persons not competent to diagnose cancer). Some medical issues require specialized training for a determination as to diagnosis and causation, and such issues are therefore not susceptible of lay opinions on etiology. Lay testimony on the question of relating the current arthritis to service is not competent in the present case, because the Veteran is not competent to state that this disease was incurred in service. See Davidson v. Shinseki, 581 F.3d 1313, 316 (Fed. Cir. 2009); Kahana v. Shinseki, 24 Vet. App. 428, 433, n. 4 (2011) (lay witnesses are competent to opine as to some matters of diagnosis and etiology, and the Board must determine on a case by case basis whether a veteran's particular disability is the type of disability for which lay evidence is competent). Such diagnoses requires clinical or diagnostic testing such as x-ray examination. X-ray examination in service and soon after service were negative. Additionally, an opinion of etiology would require knowledge of the complexities of the musculoskeletal system and the various causes of arthritis, and would involve objective clinical testing that the Veteran is not competent to perform. The Veteran also argues that his service-connected right foot disability caused or aggravated the claimed degenerative joint disease of the knees. In a November 2012 statement, the Veteran asserted that the service-connected pes planus with hammertoes at 2, 3, and 4 with heel spurs with degenerative joint disease of the talonavicular joint, bilateral with degenerative changes of the subtalar right foot. The Veteran stated in essence, that the bilateral knee disability is due to the abnormal gait form the service-connected pes planus and hammer toes. Service connection for pes planus; hammertoes at 2, 3, and 4; heel spurs; degenerative joint disease of the talonavicular joint, bilateral, and degenerative changes of the subtalar joint of the right foot were granted in March 1988 and a 30 percent rating was assigned from September 1, 1987. There is no competent medical evidence of record indicating that the current degenerative joint disease of the knees were caused or aggravated by the service-connected right foot disability. The record contains many medical treatment notations regarding the knees but at no time did a physician or other medical professional express an opinion regarding a link between the current knee disability and the service-connected right foot disability or other service-connected disability. There is competent and credible evidence which establishes that there is no relationship between the degenerative joint disease of the knees and the service-connected right foot disability. In April 2013, VA sought a medical opinion as to whether the current bilateral knee disability was proximately due to the service-connected right foot disability to include pes planus. The examiner opined that it was less likely than not that the bilateral knee disability was proximately due to or aggravated by the service-connected right foot disability. The VA examiner opined that the bilateral knee disability was consistent with the normal aging process and it was less likely that the knee disability was aggravated beyond the normal aging process. The examiner stated that there was no medically based clinical evidence to support an etiology of flat feet for the claimed knee condition. The examiner indicated that the conclusion was based upon a comprehensive review of the clinical file, CAPRI, radiographs, and current literature. The VA examiner also indicated that she was in full agreement with the January 2013 VA medical opinion in which the VA physician related the bilateral knee disability to aging and not to service. Because the Veteran does not possess the necessary medical expertise to render an opinion as to the cause of a disease, his assertions do not constitute competent evidence upon which the Board may rely. An opinion as to the etiology and onset of arthritis falls outside the realm of common knowledge of a lay person. See Jandreau, 492 F.3d at 1377 n.4 (lay persons not competent to diagnose cancer). Some medical issues require specialized training for a determination as to diagnosis and causation, and such issues are therefore not susceptible of lay opinions on etiology. There is no competent evidence which relates the current degenerative joint disease of the knees to the service-connected right foot disability. The weight of the competent and probative evidence establishes that there is no medical relationship and no aggravation. As such, service connection for degenerative joint disease of the knees as secondary to the service-connected right foot disability is denied. 38 C.F.R. § 3.310; Allen, supra. For the reasons and bases discussed above, the Board finds that a preponderance of the lay and medical evidence that is of record weighs against the claim for service connection for degenerative joint disease of the knees including as a presumptive disease, on a direct basis, and on a secondary basis, and the claim must be denied. ORDER New and material evidence having been received, the claim of entitlement to service connection for a low back disability is reopened. Service connection for degenerative joint disease and degenerative disc disease of the lumbar spine is denied. Service connection for a bilateral knee disability to include degenerative joint disease is denied. ____________________________________________ K. J. ALIBRANDO Veterans Law Judge, Board of Veterans' Appeals Department of Veterans Affairs